Evaluating the use of BECCS and afforestation under China's carbon-neutral target for 2060

Almost all global scenarios under ambitious climate targets rely on the deployment of negative emission technologies (NETs). Bioenergy with carbon capture and storage (BECCS) and afforestation are two promising NET options. However, their roles in most countries' deep decarbonization pathways and the potential economic and environmental implications have not been fully investigated. Besides, broad economic interactions and complex technical information of NETs bring challenges for traditional top-down or bottom-up models. To address the methodological issues, we integrate energy technology details into a macroeconomic framework and develop a national hybrid computable general equilibrium (CGE) model for China. Based on this, insights are provided into the deployment scale of BECCS and afforestation in China's mitigation pathways towards carbon neutrality by 2060, as well as the induced macroeconomic and land-use consequences. The results indicate that NETs are necessary for realizing carbon neutrality. BECCS would enter the market around 2030 and the share of negative emissions provided by it would reach about 79% in 2060. The carbon removals in 2060 would be 2,118 MtCO(2)yr(-1), 170 MtCO(2)yr(-1), and 617 MtCO(2)yr(-1) from bioelectricity with CCS, biofuel with CCS, and afforestation, respectively. When only BECCS is deployed as NET, more fossil energy needs to be phased out and renewable energy would take larger market shares. In 2060, most biomass would consist of cellulosic crops (43-47%) and residues (49-52%). Cropland would decrease by 6.9-8.3% due to land competition caused by NET deployment. GDP loss would be 6.4% in 2060 to reach near-zero without NETs. If BECCS and afforestation are both adopted, GDP loss would be alleviated to 4.8%. This study supplements the existing global literature to identify the local feasibility and trade-offs of NET expansion.

Automated summary

The study suggests that the deployment of negative emission technologies is necessary to achieve carbon neutrality, with BECCS entering the market around 2030 and providing about 79% of negative emissions by 2060 in China. This will reduce carbon emissions from bioenergy and afforestation, but also lead to land competition and GDP losses.